Motor uestion about turns,vs speed,vs torque

[Lmackattack]

I have used several different motors in my builds. Scales speed and power being the main goals.

My question is why does my tamiya 35 turn motor seam more powerfull than my rc4wd 80 turn motor? I thought the 80 turn would be a much better for pulling?

I put the 80 turn in my 6 wheel dump truck to get a slower scale speed and more power but it seams like it has much much less power. My 35 turn would run up a hill with a full load in the dump bed. I put the 80 turn in and it almost stalls it out?

Is it that the rc4wd is not a good quality what other mfg make a good pulling slow rpm motor?